My to-be father-in-law is offensive, judgmental, snobby, and down-right mean. Me and my fiance are getting married on a special date for us - 10 years to the day of when we became a couple. That day is also my FIL's birthday. My fiance wants us to sing happy birthday to him at the reception. Even if I liked him, I'd be against that - can't we have the day for just us this year?! Do we have to sing or is there a way out of this? If we have to, at what point in the night is appropriate?